1. Field of the Invention
The present invention relates to an auto-play apparatus for an electronic musical instrument for performing an ad-lib phrase play or a fixed phrase play of, e.g., an introduction phrase, a fill-in phrase, an ending phrase, and the like using programmed auto-play note data.
2. Description of the Related Art
An electronic keyboard (e.g., an electronic piano) normally has auto-accompaniment functions including a rhythm auto-accompaniment function, a chord or bass auto-accompaniment function, and the like. Rhythm accompaniment patterns include repetitive patterns (about two bars) such as a waltz pattern or a tango pattern, and single-phrase patterns such as an introduction phrase, a fill-in phrase or an ending phrase, which are properly inserted at desired points of a play. Another electronic musical instrument has a function (a so-called one-finger ad-lib play function) in which different phrases for about one bar are assigned to a plurality of keys, and are selectively read out in response to one-finger key operations so as to obtain an ad-lib play effect by coupling a series of phrases.
These phrase patterns are written in a ROM in advance, and can also be formed and edited by a user himself or herself.
When a user wants to edit an auto-play phrase pattern, he or she repetitively edits the pattern little by little while listening to playback tones of the editing phrase, and then determines a final pattern. The user often forms a user pattern based on phrase data written in the ROM.
When the pitches of notes constituting a phrase are shifted by about one octave during an edit operation of a user pattern, it is convenient to develop the phrase and to obtain good balance between adjacent phrases. In this case, a user must rewrite all the notes to attain the octave shift operation. Therefore, the user must determine the pitches of the notes constituting the phrase, and must have knowledge about music. When the shifted notes are restored to have original pitches, the user must rewrite all the notes again, resulting in a cumbersome edit operation.